Control means for reclosing circuit breaker

ABSTRACT

A reclosing circuit breaker having a fault overcurrent time delay means and an operation counting means. The opening time delay means selectively permits one or more fast opening operations and then, in response to a pumping force by a spring charged during a previous opening operation, blocks an oil exhaust port so that subsequent opening operations are time delayed. The operation counting means is advanced a predetermined step distance for each opening operation of the circuit breaker and is held in each advanced step until just before reclosing of the circuit breaker. The step distance advanced and the point at which the counting means is released is controlled, in part, by a simple adjustment device. Depending on its initial setting, the counting means will permit a predetermined number of circuit breaker opening operations and then will actuate a means for locking open the circuit breaker.

United States Patent 1 Rigert [541 CONTROL MEANS FOR RECLOSING CIRCUITBREAKER [75] Inventor: Max Rigert, West Allis, Wis.

[73] Assignee: McGraw-Edison Company, Elgin,

Ill.

[22] Filed: Mar. 24, 1972 21 Appl. No.: 237,732

52 us Cl. ..33s/32, 317/22, 317/59 [51] Int. Cl. ..H0lh 81/04 [58] Fieldof Search ..335/26, 27, 28, 29, 30, 32, 335/33, 34; 317/36 TD, 18 R, 33R, 22, 46, 59

[56] References Cited UNITED STATES PATENTS 3,233,067 2/1966 Rigert..335/32 3,183,331 5/1965 Barkan.... ..335/28 2,632,823 3/1953 Oppel..335/28 3,250,876 5/1966 Schultz et al. ...'...335/29 3,309,571 3/1967.Gilker ..3l7/22 [111 3,725,830 51 Apr. 3, 1973 Primary Examiner-HaroldBroome Attorney-Richard C. Ruppin [57] ABSTRACT A reclosing circuitbreaker having a fault overcurrent time delay means and an operationcounting means. The opening time delay means selectively permits one ormore fast opening operations and then, in response to a pumping force bya spring charged during a previous opening operation, blocks an oilexhaust port so that subsequent opening operations are time delayed. Theoperation counting means is advanced a predetermined step distance foreach opening operation of the circuit breaker and is held in eachadvanced step until just before reclosing of the circuit breaker. Thestep distance advanced and the point at which the counting means isreleased is controlled, in part, by a simple adjustment device.Depending on its initial setting, the counting'means will permit apredetermined number of circuit breaker opening operations and then willactuate a means for locking open the circuit breaker.

12 Claims, 3- Drawing Figures LOAD BACKGROUND OF THE INVENTION Thisinvention relates to control means for reclosing type circuit breakers.

It is common practice in electrical power systems to coordinate areclosing circuit breaker with other interrupting devices in the systemso that all of the devices will operate cooperatively to isolate only asection of the system when a fault overcurrent occurs in that section.Thus, reclosing circuit breakers are operative to execute a series ofsuccessive openin'g and reclosing operations to permit a temporary faultovercurrent to clear or to permit 'a fault in a more remote section ofthe system to be isolated by devices adjacent that section. The last oneor two opening operations of the circuit breaker are delayed to enablethe interrupting devices that are closer to the faulted section of thesystem to open and isolate the fault overcurrent to thereby enable thereclosing circuit breaker to reclose and maintain service to theimmediately adjacent section of the system. Also, reclosing circuitbreakers typically include operation counting and lockout means forpreventing reclosing of the circuit breaker after a predetermined numberof reclosing and opening operations. The reclosing circuit breaker isset to lock open after the number of opening operations at which it isconsidered that the fault is permanent in the immediate section of thesystem which the reclosing circuit breaker is intended to protect. Thisoverall mode of operation of the closing circuit breakers in electricalpower systems is well known in the art and will not be discussed infurther detail.

SUMMARY OF THE INVENTION It is a general object of the invention toprovide'a reclosing circuit breaker having a simple and efficientopening time delay means and an operation counting means which is moreaccurate in counting each opening operation of the circuit breaker thanprior art devices.

The objects of the invention are accomplished by providing a circuitbreaker contact operating means having an opening time delay means whichdelays the opening of the circuit breaker contacts in response topumping of oil by a spring and also having an operation counting meanswhich holds the position to which it is advanced following each openingoperation. When the circuit breaker opens, action of a solenoid plungerand pumping piston charges a spring which, subsequent to opening of thecircuit breaker, acts to pump oil and thereby move a member to aposition at which it blocks an oil exhaust port. The oil exhaust portaffects the rate at which the solenoid plunger and trip rod move to tripopen the circuit breaker during a subsequent opening operation. Theoperation counting means advances one predetermined step for eachopening operation of the contact operating means and holds the positionto which it is stepped for a substantial length of time while thecircuit breaker contacts are open rather than starting to return to itsinitial position immediately after being advanced to its new position.

Other objects and advantages of the invention will in part be obviousand will in part appear hereinafter. For a fuller understanding of thenature and objects of the 2 invention, reference should be made to thefollowing detailed description taken in connection with the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWING which a subsequent opening operation ofthe circuit breaker will be delayed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring generally to thedrawing, a reclosing circuit breaker is shown connected in a polyphaseelectrical power system having phases A, B, and C. The reclosing circuitbreaker includes contact operating means 2 and contact means 4 connectedin the phase lines A, B, and C. The contact means 4 preferably comprisesthree vacuum-type interrupters 4a, 4b, and 40, respectively connected inseries with the phase lines A, B, and C. The contact operating means 2includes contact rod 6 for moving the contact means 4 to an openposition as shown in FIG. 2 and a closed position as shown in FIG. 1,pivot lever means 8 for moving the contact rod 6 in opposite directionsto open and close contact means 4. The contact operating means 2 alsoincludes latchable toggle link means 10, reset means 12, closingactuation means 14, opening actuation means 16, opening time delay means18 and operation counting means 20.

The contact operating means 2 has a first position shown in FIG. 1corresponding to the closed position of the contact means 4 and a secondposition shown in FIG. 2 corresponding to the open position of thecontact means 4. The latchable toggle link 10 includes a line 22, a link24 pivoted to the link 22 at pivot point 26 and latch means 28 mountedon link 24. The latch means 28 includes a latch lever 30 and spring 32holding the latch lever 30 in a latched position. The latch means 28holds the toggle link means 10 in a substantially straight lineposition, when latched, as shown in FIG. 1 and in full lines in FIG. 2.The toggle link means 10 is prevented from collapsing in an upwarddirection relative to the view of FIG. 1 and 2 by a pin 34. The togglelink means 10 is pivotally attached at points 36 and 38 to the pivotlever means 8 and to a bell crank 40 which comprises part of the closingmeans 14.

As mentioned above, the closing actuation means 14 includes the bellcrank 40 and also includes a spring 66 attached to the bell crank 40.The bell crank 40 is pivotally mounted at pivot point 41 and has alatched counterclockwise position shown in FIG. 1 corresponding to theclosed position of contact means 4 and the first position of the contactoperating means 2. The bell crank means 40 has an unlatched clockwiseposition shown in FIG. 2 corresponding to the open position of thecontact means 4 and the second position of the contact operating means2. The opening means 16 also includes voltage means 44 having a voltagecoil 50, a voltage coil interrupting switch 46, and a potentialtransformer 48 having a secondary winding connected across two phases ofthe polyphase system and a secondary winding connected through theinterrupting switch 46 to the voltage coil 50. The voltage means 44 alsoincludes a plunger rod 52 pivotally attached to the bell crank 40 atpoint 54. The plunger rod 52 is movable in opposite vertical directionsand has an upward position and a downward position as shown in FIG. 1when the bell crank 40 is rotated to its counterclockwise position andmaintained in the counterclockwise position as shown in FIG. 1 by latchmeans 42. The latch means 42 includes a latch lever 56 and a spring 58biasing the latch lever 56 toward its latched position. The maximumdownward position of the plunger rod 52 is set by the plunger stop 60 asshown in FIGS. 1 and 2. The switch means 46 has an arm 62 and theplunger rod 52 has an arm 64 which actuates the switch means 46 to aclosed position when the plunger rod 52 moves in the direction of itsupward position. When the plunger rod 52 is in its downward position, asshown in FIG. 1, the switch means 46 is open so that the voltage coil 50is deenergized. When the voltage coil 50 is deenergized and the latchmeans 42 is unlatched, the spring 66 rotates the bell crank 40 to itsclockwise position shown in lines in FIG. 2 and moves the plunger rodtoward its upward position. When the plunger rod 52 moves to its upwardposition, it closes the switch means 46 to thereby cause energization ofthe voltage coil 50 and counterclockwise rotation of bell crank 40.Counterclockwise rotation of bell crank 40, in turn, causes movement tothe left of the substantially rigid toggle link means as shown in fulllines in FIG. 2 and pivoting of pivot lever means 8 to move the contactmeans 2 to its closed position. The switch means 46 as shown in FIG. 2is in a position just prior to being closed during upward movement ofthe plunger rod 52 in response to spring 66.

The opening actuation means 16 includes a solenoid 70 having a plunger74 and a solenoid coil 52 connected in series with one of the phases Cof the polyphase system. The opening means 14 also includes a trip rod76 having a trip finger 78 attached to the plunger 74, and an openingspring 80. The opening means 16 further includes ground overcurrentmeans 90 having overcurrent sensing and tripping means 92, electronictime delay means 88, trip rod 94, time delay selecting means 96 and.current transformer means 98. The current transformer means includesthree parallel connected current transformers 98a, 98b, and 98crespectively coupled to phaselines A, B, and C and connected to thesensing and tripping actuation means 92. The time delay selecting means96 includes a switch 100 having a stationary contact 102 and a movablecontact arm 104 biased in an upward direction relative on to the highpoint 121 of the cam surface by rotation -of the selector plate 106 aswill be described to the views of FIGS. 1 and 2. The time delayselecting A means 96 also includes a selector plate 106 pivotallymounted at 108 and having selecting holes 110, an arm 112 having an end114 selectively insertable in one of the holes 1 10 to thereby set thevertical position of arm 112,as shown in FIGS. 1 and 2, and a spring 116holding the selector plate 106 in engagement with the contact arm 112.The selector plate 106 has a cam surface 118 including a high point 121and an indentation 120 in which the contact 104 rests to therebymaintain the contact 104 disengaged from the stationary contact 102. Thecontact 104 is movable out of the indentation hereinafter.

In general, the opening actuation means 16 operates in response toeither a ground overcurrent or a phase overcurrent. In the case of aphase overcurrent, the solenoid coil 72 is energized sufficiently sothat trip finger 89 releases latch lever 30. The toggle link means 10will then collapse in a downward direction to the position shown inphantom lines in FIG. 2 in response to the force of opening spring 80.The collapse of the toggle link means 10 also permits the opening springto pivot lever means 8 in a counterclockwise direction about pivot point68 to thereby move the contact means 4 to its open position andinterrupt the flow of the current to the solenoid coil 72. Groundovercurrent will be sensed by the current transformer means 98 and thesensing and tripping actuation means 92 to thereby the art and thereforewill not be described in further detail.

The reset means 12 includes a latch trip member 126 slidably mounted onsupport 128 and pivotally connected to the pivot lever means 8 at point130. Insofar as they are utilized to reset or relatch the toggle linkmeans 10, the arm 132 of bell crank 40, the latch means 42 and thespring 66 also comprise part of the reset means 12. In the view of FIG.1, the bell crank 40 is in its counterclockwise position, the togglelink means 10 is in a substantially rigid condition and the latch tripmember 126 is spaced from the latch means 42. In the phantom view ofFIG. 2, the toggle link means 10 is collapsed, the arm 132 of bell crank40 is still in its counterclockwise position and is held in thatposition by latch means 42. However, due to the pivoting of pivotlever8, the latch trip member 126 has moved toward but not yet engaged thelatch means 42 as indicated by the phantom end line 134 of the latchtrip member 126. When the pivot lever means 8 reaches its position shownin FIG. 2, the latch trip member 126 and latch means 42 will have theirfull line position shown in FIG. 2 in which the latch trip member 126 isengaged with and unlatched the latch means 42. Upon unlatching of latchmeans 42, the arm 132 of bell crank 40 is moved clockwise under theforce of spring 66 so that the toggle link means 10 is straightened outand thereby reset in its latched condition. The toggle link means 10 isnow in condition for initiation of a reclosing operation by closingactuation means 14.

The operation counting means 20 includes a bell crank pivotally mountedat pivot point 142 and link 144 pivotally connected to bell crank 40 atpivot point 146 and slidably connected to bell crank 140 at lost motionslot 148. The operation counting means 20 pawl clockwise into engagementwith the serations 166 of ratchet rod 164, a screw 156 setting thedistance of the pawl means 150 from the ratchet rod 164 when the bellcrank 140 is in its counterclockwise position shown in FIG. 1, and ascrew 158 engaging a cam surface of the bell crank 140 as shown in FIG.2 and setting the release point of the pawl means 150 from the ratchetrod 164 when the bell crank 140 moves toward its clockwise positionshown in FIG. 2. In operation, the counting means is responsive toclockwise rotation of the bell crank 40. When the bell crank 40 is inits counterclockwise position shown in FIG. 1 and the contact means 4 isclosed, the bell crank 140 ofcounting means 20 is held in acounterclockwise position by spring 160. The pawl means 150 isrelatively downward and held away from ratchet rod 164 by screw 156.When the contact means 4 is open and the bell crank 40 rotates to itsclockwise position shown in FIG. 2, the bell crank 140 is rotated to aclockwise position by line 144 and the pawl means 150 is thereby movedupward so that screw 156 is no longer effective and spring 154 moves thepawl means 150 into engagement with one of the serations 166 of ratchetrod 164. During clockwise rotation of bell crank 140 the pawl means 150will move the ratchet rod 164 upward out of the dashpot 162 a distancedetermined by the setting of screw 158. The screw 158 engages the bellcrank 40 to release the pawl 150 from ratchet rod 164 after the desiredupward travel has taken place. A particular advantage of thisconstruction is that the pawl means 150 will hold the ratchet rod 164upward at the desired position until just prior to initiation ofreclosing of the contact means 4 by the closing actuation means 14. Inprior art devices, this holding is not obtained and the counting meanswill start to move back to its initial condition immediately after beingmoved the predetermined count distance. When the closing actuation means14 recloses the contact means'4, the link 144 moves generally in acounterclockwise direction with 7 bell crank 40 thereby permittingspring 160 to return the bell crank 140 to its counterclockwiseposition. The purpose of the lost motion slot 148 is to minimizemechanical wear on bell crank 140 by eliminating direct movement of bellcrank 140 with bell crank 40 which moves rapidly and with a considerableforce. An adjustment means 168 for setting the initial height of theratchet rod 164 is also provided.

The lock out means 17 includes double pole switch means 170 having anopening rod 172 and a trip arm 174 pivotally mounted at 176 andengageable by the ratchet rod 164 after the latter has moved upward apredetermined distance comprising the accumulated count distances causedby operation of the opening actuation means 16 and rotation of the bellcrank 40 to its clockwise position. Also depending on the initialvertical position of the ratchet rod 164 and the setting of the arm 112of time delay selecting means 96, upward movement of the ratchet rod 164will engage the arm 112 and rotate the selecting plate 106 so that themovable contact 104 will move out of the indentation 120 and on to thehigh point 121 of the cam surface 118 to thereby cause engagement ofcontacts 102 and 104. Engagement of contacts 102 and 104 causes a changein the ground overcurrent time delay means 88 so that a greater timedelay occurs before the trip rod 94 causes opening of the contact means4. The operation of the time delay selecting means 96, of course, issignificant only if the operation of the contact operating means 2 iscaused by a ground overcurrent. The internal operation of the time delaymeans 88 is well known in the art and therefore will not be discussed indetail herein.

The opening time delay means 18 is operative to provide a time delay inthe opening of the contact means 4 when a phase overcurrent occurs. Theopening time delay means 18 includes a container 180 containing a fluidsuch as oil 182 and including a first chamber 184 having exhaust ports186 and 188 and a second chamber 190 connected to chamber 184 through apassage 192 and passage means 194. Passage means 194 includes opening196, oil intake opening 198, a vertical passageway 200, and an oil ventpassage 202. Timing orifice means 224 having an adjustable opening sizealso permits escape of oil 182 from the bottom of chamber 190. The ventpassage 202 exhausts to the exterior of the container 180 through avalve 204 which opens only in response to high overcurrent actuation ofsolenoid plunger 74 and therefore high oil pressure in the bottom ofchamber 190 and in passage means 194. The operation of timing orificemeans 224 and valve 204 is well known and will not be discussed indetail. A disc valve 206 normally blocks the oil intake opening 198 anda ball valve 208 normally blocks the passage 192 adjacent its openinginto a chamber 184. The chamber 190 contains a pumping piston 210slidable in opposite vertical directions within the chamber 190 andengaging'the lower end of the solenoid plunger 74 in the upward positionof the piston 210 as shown in FIG. 1. A spring 212 is positioned in thelower end of the chamber 190 and bears against the bottom side of thepiston 210 to bias it and the solenoid plunger 74 and therefore the triprod 76 in their upward positions when the solenoid coil 72 is notenergized sufficiently to pull plunger 74 downward. When the solenoidcoil 72 is energized by an overcurrent, the solenoid plunger I 74 pushesthe piston 210 downwardly to thereby compress and charge the spring 212and pump oil 182 through the passage means 194. Valve means 214 ispositioned at the upper end of the chamber 190 and includes a disc valve216, oil inlet passages 218, springs 220 and pins 222 anchored in thewalls of container 180. The disc valve 216 is slidable on the pins 222and is biased upwardly by the springs 220 to close the oil inletpassages 218 when the piston 210 is in its upward position. When thepiston 210 moves downward, the oil pressure exteriorly of the valvemeans 214 is greater than the pressure within the chamber 190 so thatoil forces the disc valve 216 down and enters the upper part of chamber190 throughthe oil inlet passages 218.

In the first chamber 184, a sequence piston 230 is slidable in oppositevertical directions. A stem 232 is affixed to the sequence piston 230and extends vertically out of the chamber 184. The stem 232 has a seriesof spaced notches 234. An E-ring is snapped into the uppermost notch 234and bearing against a plate 238 at the upper end of chamber 184 to closethe chamber and also hold the sequence piston 230 in a vertical positionwithin chamber 184 dependent on the notch 234 in which the E-ring 236 isfastened. When the solenoid plunger 74 and piston 210 move downwardly,the

spring 212 is charged. As previously stated, downward movement of thesolenoid plunger 74 moves trip rod 76 downward to result in opening ofthe contact means 4 so that the solenoid coil 72 is deenergized. Thisfrees the solenoid plunger 74 and the piston 210 to be moved upward bythe previously compressed spring 212. The piston 210 thereby pumps oilthrough the passage 192 against ball valve 208 which moves upward topermit the oil to flow into chamber 184 against the sequence piston 230to move the sequence piston 230 a distance determined by the volume ofoil pumped underneath the piston. Also, when the piston 210 movesupwardly,

. the pressure within chamber 190 beneath piston 210 becomes less thanthat exteriorly of the container 180 so that oil bearing against thedisc valve 206 holds the disc valve 206 upwardly to result in flow ofoil into the chamber 190 and passage means 194.

The overall operation of the opening time delay means 18 may bedescribed with reference to FIGS. 1, 2, and 3. In FIG. 1, there is nophase overcurrent energizing solenoid coil 72 and therefore solenoidplunger 74 and the pumping piston 210 are in an upward position. Thesequence piston 230 is in its lowest set position as determined by thenotch to which the E-ring 236 is affixed. Upon occurrence of the phaseovercurrent, the pump piston 210 is moved downwardly, the contact means4 opens and the charged spring 212 moves the piston 210 upwardly tothereby pump oil 182 through the passage 192 and underneath the sequencepiston 230. The piston 230 then moves from an exhaust port open positionupwardly a predeter mined distance to another exhaust port openposition. Since the sequence piston 230 has not yet reached an exhaustport blocked position in which the exhaust port 186 and opening 196 areblocked, the downward movement of'the solenoid plunger 74, the trip rod76 and the piston 210 was relatively unimpeded during the previousopening operations. Therefore, the tripping of the latch means 28 andopening of contact means 4 occurred quickly after energization ofsolenoid coil 72 by the overcurrent. Assuming the phase overcurrentcondition continues to be present after the initial opening and closingoperation of the reclosing circuit breaker and the lockout means 17 doesnot operate, at least one more relatively fast downward pumpingoperation by piston 210 and upward pumping operation by the same pistonin response to spring 212 to advance sequence piston 230 one more stepwill occur. However, on the last upward advancement of the sequencepiston 230, it moves to a blocked position in which the exhaust port 186is blocked and will not permit passage of oil from the chamber 184. Inthe blocked position of the sequence piston 230, however, the exhaustport 188 is partially open so that subsequent upward movement of piston210 can occur due to flow of oil abovepiston 210 through passage 192 andultimately out of port 188. If the phase overcurrent condition continuesto exist the next downward movement of the solenoid plunger 74 andpiston 210 will be retarded since only timing orifice means 224 andvalve 204 are available to permit escape of oil 184 from beneath piston210. This consequently delays tripping of latch means 28 and opening ofcontact means 4. During the open operations of the circuit breaker, theoperation counting means 20 has been operating. Accordingly, if thecounting means has been set by adjustment means 168 to move the lockouttrip arm 174 upward into engagement with opening rod 172, after fouropenings, the switch means will open and the circuit breaker will beprevented from again closing. 1

It may be noted at this point that in the event that the phaseovercurrent condition ceases prior to lockout of the closing circuitbreaker, the contact means 4 will remain closed, the solenoid 70 willnot operate, and the sequence piston 230 will settle back down to itsinitial position as oil 182 escapes from the bottom of chamber 184around the sequence piston and out the ports 186 and 188. Also, if theovercurrent ceases before lockout occurs, the ratchet rod 164 willsettle back down into dashpot 162 to its initial position.

While only a single specific embodiment of the invention has been shownherein, it will be realized that many modifications thereof are feasiblewithout departing from the spirit and scope of the invention. It isaccordingly intended that the scope of the invention is not to belimited tothe specificembodiment disclosed.

1 claim: I

1. In a reclosing circuit breaker including contact means having an openand closed position andbeing connected in an electrical power system,the combination comprising:

contact operating means having first and second positions respectivelycorresponding to the closed and open positions of the contact means andincluding: closing means connected to said system for actuating thecontact operating means to close the contact means and movingthe contactoperating means from said second position to said first position;opening means connected to said, system for actuating the contactoperating means to close the contact means and moving the contactoperating means from said first position to said second position; and 1operation counting means having a plurality of 1 positions and beingsequentiaily advanceable to a different one of said positions inresponse to the contact operating means during each move,- ment of thelatter from said first to said second position for counting the numberof opening operations of said contact means, said operation countingmeans being stationary in one of said positions subsequent toadvancement thereto in response to said contact operating means. i

2. The combination according to claim 1 wherein said operation countingmeans is stationary in each of said positions in response to the closingmeans.

3. The combination according to claim 1 wherein said operation countingmeans is releasable from each one of said positions at a selectivelypredetermined point in the movement of the contact operating means.

4. The combination according to claim 3 wherein said operation countingmeans has an initial position, a final position and is effective toprevent operation of said closing means when in said final position.

5. The combination according to claim 4 wherein said operation countingmeans comprises an elongated ratchet member and a pawlmovable intoengagement with the ratchet member, said ratchet member and pawl beingmovable in a direction together substantially parallel to the length ofthe ratchet member, said pawl being disengagable from said ratchetmember at each one of said positions, the movement of said pawl andratchet member together and the disengagement of the pawl from theratchet member being in response to the closing means.

6. The combination according to claim 1 further comprising time delaymeans for delaying opening actuation of the contact means, said timedelay means including a container having first and second connectedchambers, fluid in said container, a fluid exhaust port in said firstchamber, a movable member in said first chamber and having an exhaustport open position and an exhaust port blocked position, spring meansresponsive to said opening means for providing force to pump fluidagainst said movable member to move the latter from the exhaust portopen position to the exhaust port blocked position, and piston meansmovable in said second chamber and having a retarded movement conditionwhen the exhaust port is blocked for delaying operation of the openingmeans whereby opening of the contact means is also delayed.

7. In a reclosing circuit breaker including contact means having an openand closed position and being connected in an electrical power system,the combination comprising:

contact operating means for closing and opening the contact means, saidcontact operating means including:

closing actuating means connected to said system for actuating thecontact operating means to close the contact means;

opening actuating means connected to said system and movable between afirst position to a second position for actuating the contact operatingmeans to open the contact means; and

time delay means for delaying opening actuation of the contact operatingmeans, said delay means including a container having first and secondconnected chambers, fluid in said container, a fluid exhaust port insaid first chamber, a movable member in said first chamber and having anexhaust port open position and an exhaust port blocked position, springmeans responsive to said opening actuating means for providing force topump fluid against said movable member to move the latter from theexhaust port open position to the exhaust port blocked position, andpiston means movable in said second chamber and having a retarded movement condition when the exhaust port is blocked for delaying operationof the opening actuation means whereby opening of the contact means isalso delayed.

8. The combination according to claim 7 wherein: said spring means is insaid second chamber and has a charged condition, said springs beingmoved to the charged condition in response to movement of the openingactuation means from its first to its second position; and

said piston means is movable in response to movement of the openingactuation means from its first to its second position to pump fluid outof said exhaust port when the latter is open, said piston means having anon-retarded movement condition when the exhaust port is open wherebyopening the contact means is relatively non-delayed following operationof the opening actuation means.

9. The combination according to claim 7 wherein said piston means ismovable in a first direction in response to movement of the openingactuation means to pump fluid out of said container and is movable in anopposite direction in response to said spring means to pump fluidagainst said movable member in the first chamber.

10. The combination according to claim 9 wherein:

said container includes a first passage connecting opposite ends of thefirst and second chambers and a second passage connecting the otheropposite ends of the first and second chambers; movement of the pistonmeans in its first direction pumps fluid through the first passage, andout of the container through the exhaust port when the movable member isin its exhaust port open position, pumping of fluid by the piston meansthrough the first passage and exhaust port being blocked when themovable member is in its exhaust port blocked condition; and i movementof the piston means in its opposite direction pumps fluid through thesecond passage against the movable member to move the latter toward itsexhaust port blocked position.

11. The combination according to claim 7 further comprising: I

operation counting means for counting the number of opening operationsof said contact means; and

wherein said opening actuation means includes:

electronic time delay means responsive to a ground overcurrent in saidsystem for delaying opening actuation of the contact operating means,said electronic time delay means having an initial condition in which notime delay is provided and a time delay condition; and

time delay selecting means responsive to said operation counting meansto modify the electronic time delay means from its initial to its timedelay condition.

12. The combination according to claim 1 1 wherein;

said contact operating means has first and second positions respectivelycorresponding to the closed and open positions of the contact means;

said operation counting means has a plurality of positions and issequentially advanceable to a different one of said positions inresponse to the contact operating means during each movement of thelatter from said first to said second position; and said time delayselecting means comprises switch means having a stationary contact and amovable contact finger having disengaged and engaged positions formodifying said electronic time delay means when the stationary contactand movable contact finger are in their engaged position, selector meanshaving a cam surface including a high point and an indentation andnormally engaging the contact-finger at said indentation for moving thecontact finger from said disengaged to said engaged position, springmeans for maintaining the selector means in engagement with the contactfinger, arms means positioned for engagement with said operationcounting means as the latter which the movable contactfinger of theswitch advances, said arm means being selectively posiv means engagesthe high point of said cam'surface tionable on the selector meanswhereby the posiand is in the engaged position with the stationary tionat which the operation counting means contact whereby the electronictime delay means gages h arm means may b determined, i arm is modifiedfrom its initial condition to its tim means being effective in responseto movement of delay condltlonr the operation counting means to aposition at

1. In a reclosing circuit breaker including contact means having an openand closed position and being connected in an electrical power system,the combination comprising: contact operating means having first andsecond positions respectively corresponding to the closed and openpositions of the contact means and including: closing means connected tosaid system for actuating the contact operating means to close thecontact means and moving the contact operating means from said secondposition to said first position; opening means connected to said systemfor actuating the contact operating means to close the contact means andmoving the contact operating means from said first position to saidsecond position; and operation counting means having a plurality ofpositions and being sequentially advanceable to a different one of saidpositions in response to the contact operating means during eachmovement of the latter from said first to said second position forcounting the number of opening operations of said contact means, saidoperation counting means being stationary in one of said positionssubsequent to advancement thereto in response to said contact operatingmeans.
 2. The combination according to claim 1 wherein said operationcounting means is stationary in each of said positions in response tothe closing means.
 3. The combination according to claim 1 wherein saidoperation counting means is releasable from each one of said positionsat a selectively predetermined point in the movement of the contactoperating means.
 4. The combination according to claim 3 wherein saidoperation counting means has an initial position, a final position andis effective to prevent operation of said closing means when in saidfinal position.
 5. The combination according to claim 4 wherein saidoperation counting means comprises an elongated ratchet member and apawl movable into Engagement with the ratchet member, said ratchetmember and pawl being movable in a direction together substantiallyparallel to the length of the ratchet member, said pawl beingdisengagable from said ratchet member at each one of said positions, themovement of said pawl and ratchet member together and the disengagementof the pawl from the ratchet member being in response to the closingmeans.
 6. The combination according to claim 1 further comprising timedelay means for delaying opening actuation of the contact means, saidtime delay means including a container having first and second connectedchambers, fluid in said container, a fluid exhaust port in said firstchamber, a movable member in said first chamber and having an exhaustport open position and an exhaust port blocked position, spring meansresponsive to said opening means for providing force to pump fluidagainst said movable member to move the latter from the exhaust portopen position to the exhaust port blocked position, and piston meansmovable in said second chamber and having a retarded movement conditionwhen the exhaust port is blocked for delaying operation of the openingmeans whereby opening of the contact means is also delayed.
 7. In areclosing circuit breaker including contact means having an open andclosed position and being connected in an electrical power system, thecombination comprising: contact operating means for closing and openingthe contact means, said contact operating means including: closingactuating means connected to said system for actuating the contactoperating means to close the contact means; opening actuating meansconnected to said system and movable between a first position to asecond position for actuating the contact operating means to open thecontact means; and time delay means for delaying opening actuation ofthe contact operating means, said delay means including a containerhaving first and second connected chambers, fluid in said container, afluid exhaust port in said first chamber, a movable member in said firstchamber and having an exhaust port open position and an exhaust portblocked position, spring means responsive to said opening actuatingmeans for providing force to pump fluid against said movable member tomove the latter from the exhaust port open position to the exhaust portblocked position, and piston means movable in said second chamber andhaving a retarded movement condition when the exhaust port is blockedfor delaying operation of the opening actuation means whereby opening ofthe contact means is also delayed.
 8. The combination according to claim7 wherein: said spring means is in said second chamber and has a chargedcondition, said springs being moved to the charged condition in responseto movement of the opening actuation means from its first to its secondposition; and said piston means is movable in response to movement ofthe opening actuation means from its first to its second position topump fluid out of said exhaust port when the latter is open, said pistonmeans having a non-retarded movement condition when the exhaust port isopen whereby opening the contact means is relatively non-delayedfollowing operation of the opening actuation means.
 9. The combinationaccording to claim 7 wherein said piston means is movable in a firstdirection in response to movement of the opening actuation means to pumpfluid out of said container and is movable in an opposite direction inresponse to said spring means to pump fluid against said movable memberin the first chamber.
 10. The combination according to claim 9 wherein:said container includes a first passage connecting opposite ends of thefirst and second chambers and a second passage connecting the otheropposite ends of the first and second chambers; movement of the pistonmeans in its first direction pumps fluid through the first passage, andout of the container through the exhaust port when the movable member isin its exhaust port open position, pumping of fluid by the piston meansthrough the first passage and exhaust port being blocked when themovable member is in its exhaust port blocked condition; and movement ofthe piston means in its opposite direction pumps fluid through thesecond passage against the movable member to move the latter toward itsexhaust port blocked position.
 11. The combination according to claim 7further comprising: operation counting means for counting the number ofopening operations of said contact means; and wherein said openingactuation means includes: electronic time delay means responsive to aground overcurrent in said system for delaying opening actuation of thecontact operating means, said electronic time delay means having aninitial condition in which no time delay is provided and a time delaycondition; and time delay selecting means responsive to said operationcounting means to modify the electronic time delay means from itsinitial to its time delay condition.
 12. The combination according toclaim 11 wherein; said contact operating means has first and secondpositions respectively corresponding to the closed and open positions ofthe contact means; said operation counting means has a plurality ofpositions and is sequentially advanceable to a different one of saidpositions in response to the contact operating means during eachmovement of the latter from said first to said second position; and saidtime delay selecting means comprises switch means having a stationarycontact and a movable contact finger having disengaged and engagedpositions for modifying said electronic time delay means when thestationary contact and movable contact finger are in their engagedposition, selector means having a cam surface including a high point andan indentation and normally engaging the contact finger at saidindentation for moving the contact finger from said disengaged to saidengaged position, spring means for maintaining the selector means inengagement with the contact finger, arms means positioned for engagementwith said operation counting means as the latter advances, said armmeans being selectively positionable on the selector means whereby theposition at which the operation counting means engages the arm means maybe determined, said arm means being effective in response to movement ofthe operation counting means to a position at which the movable contactfinger of the switch means engages the high point of said cam surfaceand is in the engaged position with the stationary contact whereby theelectronic time delay means is modified from its initial condition toits time delay condition.